Late Quaternary glacial chronology on the eastern slope of Gongga Mountain,eastern Tibetan Plateau,China  

作　　者：WANG Jie PAN BaoTian ZHANG GuoLiang CUI Hang CAO Bo GENG HaoPeng 

机构地区：[1]Key Laboratory of Western China's Environmental Systems(Ministry of Education),Lanzhou University

出　　处：《Science China Earth Sciences》2013年第3期354-365,共12页中国科学（地球科学英文版）

基　　金：supported by National Natural Science Foundation of China(Grant No.41171063);Fundamental Research Funds for the Central Universities(Grant No.LZUJBKY-2010-114);Foundation of State Key Laboratory of Cryospheric Sciences,Cold and Arid Regions Environment and Engineering Research Institute,Chinese Academy Sciences(Grant No.SKLCS2011-03);the Program of Ministry of Science and Technology of China(Grant No.2006FY110200)

摘　　要：The Gongga Mountain is the largest area of modern glaciation in the Hengduan Mountains and,with a summit elevation of 7556 m,is the highest mountain on the eastern margin of the Tibetan Plateau.During the Quaternary glacial-interglacial cycles the Gongga Mountain was extensively and repeatedly glaciated,and glacial landforms and outwash deposits from multiple glaciations are well-preserved in valleys,in basins,and on piedmonts.To constrain the glacial chronology of the eastern slope of Gongga Mountain,sample sites were selected based on the distribution and weathering of glacial tills,relationships among glacial deposits,and soil development on moraines.Dating of the tills and glaciofluvial deposits was undertaken with electron spin resonance(ESR) and optically stimulated luminescence(OSL).The ages of the glacial deposits can be divided into four clusters:2.2±0.5,11.9±0.6,35.9±2.7-58.0±6.3 and 119.2±15.9-194.2±32.8 ka.Five glacial advances in this region have been identified,which are equivalent in age to the Little Ice Age(LIA),Neoglaciation,marine oxygen isotope stage(MIS) 2,mid-MIS3,and MIS6.The largest local last glacial maximum(LGML) occurred on Gongga Mountain during mid-MIS3,characterized by a cold-humid climate,rather than the global Last Glacial Maximum(LGMG) of MIS2.The Gongga,Nanmenguangou(NMGG) and Yajiageng Glaciations occurred during the late part of the last glacial cycle,the middle of the last glacial cycle and the penultimate glacial cycle,respectively.On the basis of geomorphological,sedimentological,and compositional characteristics,landforms of the Moxi Platform and terraces can be grouped by facies and geochronology.In combination with the dating results,this analysis indicates the basal part of the Moxi Platform between Xinxin and the Moxi Hotel is correlative with the till of the Nanguanmen Glaciation(mid-MIS3).This basal unit has occasional lenses of glaciofluvial sandy gravel and lacustrine sediments.The remainder of the Moxi Platform and the terraces beside the platform are glaciofThe Gongga Mountain is the largest area of modern glaciation in the Hengduan Mountains and, with a summit elevation of 7556 m, is the highest mountain on the eastern margin of the Tibetan Plateau. During the Quaternary glacial-interglacial cycles the Gongga Mountain was extensively and repeatedly glaciated, and glacial landforms and outwash deposits from multiple glaciations are well-preserved in valleys, in basins, and on piedmonts. To constrain the glacial chronology of the eastern slope of Gongga Mountain, sample sites were selected based on the distribution and weathering of glacial tills, relationships among glacial deposits, and soil development on moraines. Dating of the tills and glaciofluvial deposits was undertaken with electron spin resonance （ESR） and optically stimulated luminescence （OSL）. The ages of the glacial deposits can be divided into four clusters： 2.2±0.5, 11.9±0.6, 35.9±2.7,58.0±6.3 and 119.2±15.9-194.2±32.8 ka. Five glacial advances in this region have been identified, which are equivalent in age to the Little Ice Age （LIA）, Neoglaciation, marine oxygen isotope stage （MIS） 2, mid-MIS3, and MIS6. The largest local last glacial maximum （LGML） occurred on Gongga Mountain during mid-MIS3, char- acterized by a cold-humid climate, rather than the global Last Glacial Maximum （LGMG） of MIS2. The Gongga, Nanmen- guangou （NMGG） and Yajiageng Glaciations occurred during the late part of the last glacial cycle, the middle of the last gla- cial cycle and the penultimate glacial cycle, respectively. On the basis of geomorphological, sedimentological, and composi- tional characteristics, landforms of the Moxi Platform and terraces can be grouped by facies and geochronology. In combina- tion with the dating results, this analysis indicates the basal part of the Moxi Platform between Xinxin and the Moxi Hotel is correlative with the till of the Nanguanmen Glaciation （mid-MIS3）. This basal unit has occasional lenses of glaciofluvial sandy gravel and lacustrine sedime

关 键 词：ESR dating glacial chronology Gongga Mountain Moxi Platform OSL dating 

分 类 号：P343.6[天文地球—水文科学] Q959.53[天文地球—地球物理学]